This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A261403 #13 Dec 12 2023 08:19:25 %S A261403 1,12,4,0,0,-24,-16,0,-8,-36,24,0,0,72,-32,0,24,24,52,0,0,0,-48,0,-32, %T A261403 -12,56,0,0,-120,-96,0,24,0,72,0,0,-24,-80,0,-48,120,128,0,0,72,-96,0, %U A261403 96,-84,124,0,0,168,-160,0,-64,0,120,0,0,-120,-128,0,24,-144,192,0,0,0,-192 %N A261403 Coefficients of an example of a modular form of weight 2 for the group Gamma_0(32). %C A261403 This is a particular member of an eight-dimensional vector space. %H A261403 Robin Visser, <a href="/A261403/b261403.txt">Table of n, a(n) for n = 0..1000</a> %H A261403 John F. R. Duncan, Michael J. Griffin and Ken Ono, <a href="http://arxiv.org/abs/1503.01472">Proof of the Umbral Moonshine Conjecture</a>, arXiv:1503.01472, 2015, See Eq. (B.88). %o A261403 (Sage) %o A261403 def a(n): %o A261403 B = ModularForms(Gamma0(32),2).basis() %o A261403 f = B[1] + 12*B[0] + 4*B[3] - 16*B[6] - 8*B[7] %o A261403 return f.coefficient(n) # _Robin Visser_, Dec 12 2023 %Y A261403 Cf. A002171. %K A261403 sign %O A261403 0,2 %A A261403 _N. J. A. Sloane_, Aug 20 2015 %E A261403 More terms from _Robin Visser_, Dec 12 2023